U.S. Pat. No. 5,611,173 to Headrick et al. discloses a threshold having a threaded pedestal 32 and support pad 33 as well as a correspondingly threaded lug 34 adapted to receive the threaded pedestal 32. See, FIGS. 2 and 6 of the '173 patent. Also see U.S. Pat. Nos. 5,588,266 and 5,426,894 to Headrick. Each of the foregoing patents discloses a lug 34 captured in a slot which cooperates with a threaded pedestal to vertically raise and lower a threshold.
U.S. Pat. No. 6,345,477 to Keppler et al. discloses a series of screws 64 and nuts 66. According to the '477 specification: “Nuts 66 fit within the channel below web 68 between the adjacent sides. Nuts 66 are sufficiently large so that they are prohibited from turning and may transmit an axial load along the screw axis to web 68.” Rotation of the screws 64 adjust the height of the threshold.
Each of the following United States Patents disclose an adjustable threshold: U.S. Pat. No. 4,387,535; U.S. Pat. No. 4,074,464; U.S. Pat. No. 5,524,391; U.S. Pat. No. 5,517,788; U.S. Pat. No. 5,179,804; U.S. Pat. No. 4,447,987; U.S. Pat. No. 4,476,653; U.S. Pat. No. 4,945,680; U.S. Pat. No. 5,136,814; U.S. Pat. No. 3,962,828; U.S. Pat. No. 3,967,412; and U.S. Pat. No. 4,352,258. These disclosures are indicative of the state of the art.
A particular problem in the dispensation of adjustable threshold fasteners is the fact that they tend to jam in the curvilinear track which feeds the insertion mechanism. See, FIG. 2 in this application for patent which illustrates jamming of the fasteners in the feed track. Referring to FIG. 2, adjacent fasteners are illustrated in a shingling fashion such that the higher fastener wedges underneath the adjacent lower fastener. Shingling can also occur such that the higher fastener rides up above the adjacent lower fastener.
FIG. 2 is a side view 200 of the interior of a section of a curvilinear track 223 with several prior art fasteners 100 located therein. FIG. 2 illustrates a head-guide 221, a nut-guide 222, and a rimmed edge 220. Typically, the track 223 is gravity fed with fasteners. The weight, momentum and inertia of a plurality of fasteners apply pressure to the fasteners when they abruptly stop in the track due to a stoppage in the demand for the fasteners. Additionally, variance in the dimensions of the fasteners is a contributing cause to the shingling and jamming of the fasteners.
FIG. 2A is an end view 200A of the track of FIG. 2 illustrating a prior art fastener therein. The insertion mechanism press-fits a threaded stud into and through a wall of the threshold. The stud is then rotatably adjustable with respect to the wall. The materials of the threshold may be plastic, wood or metal and the material of the threaded stud is plated steel. A reciprocally threaded nut is also carried with the stud and when the stud is inserted into the threshold, one surface of the nut engages the threshold. The threaded stud has two ends and may be rotated from either end thereof. When the stud is rotated it has the effect of extending the support surface away from the threshold enabling the threshold to be adjusted vertically.
FIG. 1 is a side view of a prior art adjustable fastener 100 illustrating a bolt head or support surface 101, a neck 115, a rectangularly shaped nut 102, threaded shaft 103 and an adjustment 104 adapted to receive a screw driver. Although the adjustment 104 is oriented at the bottom of FIG. 1, when the adjustable fastener is press-fit into a threshold, the orientation of the fastener is reversed. In other words the fastener is oriented 180 degrees from that shown in FIG. 1.
FIG. 1A is a top view 100A of the prior art fastener of FIG. 1 illustrating adjustment 105 which is adapted to receive a screw driver. FIG. 1B is a perspective view 100B of the prior art fastener of FIG. 1. FIG. 1C is a cross-sectional view 100C of the prior art fastener taken along lines 1C-1C of FIG. 1A. FIG. 1D is an end view 100D of the prior art fastener of FIG. 1 and FIG. 1E is a bottom view 100E of the prior art fastener of FIG. 1.
Given the foregoing prior art, it is desirable to have an adjustable threshold fastener which is capable for delivery by a feed track without jamming the feed track.